Weapons are often equipped with interchangeable barrels. After a cartridge is ignited, a projectile is pushed through a passageway of the barrel creating vibration and stress that is absorbed through oscillations of the barrel. During continuous firing or rapid projectile releases, overheating of the barrel may result due to friction energy from the projectile in the barrel and gas pressure from igniting the propellant in the cartridges. In some instances, overheating of the barrel can result in a gas pressure inside of an ignited cartridge shell to increase to a level that causes the cartridge shell to break apart and, thus, block a cartridge chamber. Additionally, continuous firing, especially of high caliber ammunition such as machine guns and grenade launchers, increases the temperature of the barrel causing the barrel to expand and, thus, reducing shot precision and hit rate.
Known weapons have been provided with interchangeable barrels that are able to be interchanged regardless of the number of shots fired. Typically, the interchangeable barrel is bolted with a holding bracket or coupled to the holding bracket in another manner. The rear end of the interchangeable barrel is provided with a cartridge chamber where cartridges are loaded and ignited (e.g., fired). Igniting rounds in the cartridge chamber produces high gas pressure and, therefore, the walls of the cartridge chamber are typically stronger than that of the interchangeable barrel. If the cartridge is in the correct position in the cartridge chamber while the cartridge is ignited, the cartridge shell can seal the gas pressure in the barrel. Typically, the cartridge chamber forms a negative imprint on the cartridge shell that is typically made of a relatively soft and flexible copper-brass-alloy. After the cartridge is ignited, the cartridge shell normally conforms exactly to the walls of the cartridge chamber and, thus, seals the gas pressure produced within the interchangeable barrel.
Alternatively, if the interchangeable barrel is not correctly mounted, bolted and/or locked on the holding bracket due to, for example, operating errors, the cartridge shell will not correctly fit into the cartridge chamber and, therefore, the cartridge shell will not seal the gas pressure in the interchangeable barrel. This may cause the firing pin not to reach a cap of the cartridge preventing the release of the projectile and causing a jam. Alternatively, if the firing pin reaches the cap and an ignition takes place, the non-sealed gas pressure can cause the barrel to explode causing serious injury to the operator.
There is a large selection of known safety mechanisms related to trigger mechanisms, locking systems, etc. that have the intention of preventing an automatic or unintentional ignition of a cartridge. However, in weapons with interchangeable barrels, these known safety mechanisms do not prevent shots from being fired if interchangeable barrel is not correctly mounted, bolted and/or locked and, thus, they create a considerable danger for the weapon operator and/or other bystanders.
A known example, DE 35 41 312 C2, describes a locking mechanism that interacts with a firing pin locking device so that a firing pin is blocked and is unable to reach the cartridge head if the barrel is released. Additionally, DE 35 41 312 C2 describes a release clamp to lock and release the barrel of portable automatic firearms that blocks a weapon lock if the barrel is released.